It is not only about the view from the top; the the journey and the activities on offer are an important part.
Starting with views, I love the views over the lake from Rigi. I assume Pilatus has similarly beautiful lake views, just from a different angle. I haven’t been on Titlis since skiing there more than 50 years ago, and I did not reach the top on that trip. But I don’t think one can see the lake from there.
Activities adventures, and the journey:
Titlis probably has the most variety if activities, including adventurous ones. But you may pay extra for certain choices.*** The journey is a simple one by train, and the easiest from Lauterbrunnen.
https://www.titlis.ch/en
For Pilatus, you can take the cogwheel train from Alpnachstad, reached by train from Interlaken Ost. This would be strictly a mountaintop visit ( similar to Schilthorn), unless you choose to ride the lifts down to Kriens, stopping at the Frakmuntegg Adventure Park on the way. Then return to Lauterbrunnen from Luzern.
https://www.pilatus.ch/en/
Rigi offers the most variety in terms of the journey—-train to Luzern, boat to Vitznau, cogwheel train to the summit, back down to Rigi Kaltbad by train (or walk), steel cablecar down to Weggis, and boat back to Luzern to catch the train back to Lauterbrunnen. Hiking is the main activity here, not ropes courses and cliff walks. But you have that beautiful view over the lake. And a spa opportunity at Rigi Kaltbad.
https://www.rigi.ch/en
There are different travel times and different costs involved in each, so check all those before you decide, so you don’t get an unwelcome surprise. Note that the Rigi roundtrip (boat, cogwheel train, and cablecar) are all fully covered with a Swiss Pass, but not with a Berner Oberland Pass. The BO Pass will cover your train as far as Luzern.
Your Half Fare card will give you 50% off everything in the way of transport, but not extra activities.
*** Here is the price list for Titlis activities and lifts, including applicable discounts:
